1. Field of the Invention
The invention relates to a sliding articulation, which can be used in articulated shafts of motor vehicles or the like, having an outer hub that surrounds a cavity and has raceways in its inner surface, which extend parallel to the axis of the sliding articulation, an inner hub accommodated in the cavity, which has raceways on its outer surface, which extend parallel to the axis of the sliding articulation and lie opposite the raceways of the outer hub, and accommodate a ball together with these, in pairs, in each instance, and having a cage disposed between the outer hub and the inner hub, which guides the balls in an axial direction.
2. The Prior Art
In articulated shafts, which are used, for example, as longitudinal shafts or lateral shafts in motor vehicles, to transfer a drive torque from the transmission to the drive wheels, it is usual to allow a change in length of the shaft for assembly purposes or to equalize axial movements during operation. In DE 199 11 111 C1, for example, an arrangement having a synchronous fixed articulation is proposed, which has a slide journal and a slide sleeve segment that surrounds the latter, both of which have grooves for accommodating balls, which grooves are assigned to one another. The slide journal is connected with the slide sleeve segment so as to rotate with it, by means of these balls, while an axial movement of the slide journal relative to the slide sleeve segment is possible. However, the construction space required for such an arrangement is large, because of the separation of the articulation from the sliding unit.
An articulation of the type stated initially is known from DE patent 2 114 536, which allows the equalization of angles of inclination of two shaft ends, as a synchronous articulation and, at the same time, as a sliding articulation, allows an axial change of the distance between the shaft ends, relative to one another. The cage of this articulation is provided with an outer ball surface that is guided in an inner ball surface of the outer hub, so that the cage is held in the outer hub in the axial direction. As a result, a movement of the balls accommodated in the raceways, relative to the outer hub, is not possible, so that the balls cannot roll in the raceways, and instead a relative movement between the outer hub and the inner hub is only possible by means of a displacement of the balls in the raceways of the inner hub. Displacement of the balls in the raceways results in high friction moments in the articulation, which result in heating during operation and more rapid wear.
It is therefore the task of the invention to make available a sliding articulation of the type stated initially, in which the friction in operation is reduced, while at the same time, it allows the relative movement between the inner hub and the outer hub that is required for assembly.